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Fan D, Liu L, Yuen B, Sun L, Fu Y, Liu Y, Liao R, Qu Y, Liu C, Zhou Q. An Additional L451G452N453 in the RpoB Protein Suppressed the Synthetic Lethality in Escherichia coli at 37 Degrees Caused by Depletion of DnaK/J and Trigger Factor. J Basic Microbiol 2024:e2400253. [PMID: 39286860 DOI: 10.1002/jobm.202400253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 08/16/2024] [Accepted: 09/03/2024] [Indexed: 09/19/2024]
Abstract
Escherichia coli depletion of chaperone trigger factor and DnaK/J were not viable at 37°C, but viable below 30°C. Among the engineered E. coli depleted of trigger factor and DnaK/J, one strain Z625, exhibited survival at 37°C, while another strain Z629 only survived below 30°C. Comparative analysis of fatty acid profiles of Z625 and Z629 revealed absence of numerous saturated fatty acids in Z625 as compared to the wild-type E. coli BW25113. In addition, increased unsaturated fatty acids were present in Z625, whereas the fatty acids profile of Z629 closely resembled that of BW25113. Whole genome sequencing revealed a 9-bp insertion in rpoB of Z625. Combined structural analysis of simulated RpoB protein bearing the amino acid sequence L451G452N453 insertion and susceptibility analysis to rifampicin suggested that the insertion did not disturb the individual RpoB structure as beta subunit of RNA polymerase. Comparative transcriptomic analysis of Z625 and Z629 suggested that this insertion impacted transcription of the overall RNA polymerase in Z625, leading to potential repression of some genes whose overexpression was toxic to E. coli. Additionally, Z625 exhibited distinctive metabolic adaptations, likely contributing to its survival at 37°C. In summary, our study elucidated one LGN insertion in rpoB that impacts transcriptional regulation in E. coli, thereby explaining the survival of E. coli depletion of trigger factor and DnaK/J at 37°C, and these founding suggested that some simple mutations in critical genes like rpoB might play an important role in driving adaptive evolution.
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Affiliation(s)
- Dongjie Fan
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Lushan Liu
- Emergency Department of China Rehabilitation Research Center, Fengtai District, Capital Medical University, Beijing, China
| | - Bella Yuen
- Faculty of Arts and Science, University of Toronto, Toronto, Ontario, Canada
| | - Lu Sun
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yuliang Fu
- Department of Orthopaedics, Peking University Third Hospital, Beijing, China
| | - Yan Liu
- Peking University Health Science Center, Beijing, China
| | - Rui Liao
- Beijing Best HealthCare Medical Technology Co. Ltd., Economic and Technological Development Area, Beijing, China
| | - Yanli Qu
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Chuanpeng Liu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Qiming Zhou
- Beijing ChosenMed Clinical Laboratory Co. Ltd., Economic and Technological Development Area, Beijing, China
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Molecular Effects of Elongation Factor Ts and Trigger Factor on the Unfolding and Aggregation of Elongation Factor Tu Induced by the Prokaryotic Molecular Chaperone Hsp33. BIOLOGY 2021; 10:biology10111171. [PMID: 34827164 PMCID: PMC8614738 DOI: 10.3390/biology10111171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 12/13/2022]
Abstract
Simple Summary Proteins are versatile biological macromolecules involved in most biological processes. However, because of the highly labile nature of protein structures, protein quality control (PQC) to ensure proteostasis (i.e., protein homeostasis)is difficult. Therefore, proteins of a specialized class (i.e., molecular chaperones) are required that assist in proper folding and prevent aberrant folding of other proteins. Hsp33 was originally discovered as a holding chaperone that is overexpressed upon heat shock and activated by oxidation to prevent the misfolding of client proteins. Recently, an unfoldase/aggregase activity of Hsp33 was identified in its reduced state against a specific substrate, EF-Tu, which plays a key role in protein biosynthesis in cells. The present study demonstrates that EF-Tu unfolding/aggregation by Hsp33 can be accelerated by another molecular chaperone trigger factor. Given that the unfolded/aggregated EF-Tu is finally degraded by another chaperone, Lon protease, it is likely that a chaperone network dysregulating EF-Tu operates in heat shock to attenuate protein biosynthesis, which is harmful to cell survival under stressed conditions. Therefore, the apparently contradictory chaperone function (i.e., promotion of client misfolding) of Hsp33 can also be associated with the PQC processes to ensure proteostasis in cells. Abstract Hsp33, a prokaryotic redox-regulated holding chaperone, has been recently identified to be able to exhibit an unfoldase and aggregase activity against elongation factor Tu (EF-Tu) in its reduced state. In this study, we investigated the effect of elongation factor Ts (EF-Ts) and trigger factor (TF) on Hsp33-mediated EF-Tu unfolding and aggregation using gel filtration, light scattering, circular dichroism, and isothermal titration calorimetry. We found that EF-Tu unfolding and subsequent aggregation induced by Hsp33 were evident even in its complex state with EF-Ts, which enhanced EF-Tu stability. In addition, although TF alone had no substantial effect on the stability of EF-Tu, it markedly amplified the Hsp33-mediated EF-Tu unfolding and aggregation. Collectively, the present results constitute the first example of synergistic unfoldase/aggregase activity of molecular chaperones and suggest that the stability of EF-Tu is modulated by a sophisticated network of molecular chaperones to regulate protein biosynthesis in cells under stress conditions.
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Fauvet B, Finka A, Castanié-Cornet MP, Cirinesi AM, Genevaux P, Quadroni M, Goloubinoff P. Bacterial Hsp90 Facilitates the Degradation of Aggregation-Prone Hsp70-Hsp40 Substrates. Front Mol Biosci 2021; 8:653073. [PMID: 33937334 PMCID: PMC8082187 DOI: 10.3389/fmolb.2021.653073] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/17/2021] [Indexed: 01/27/2023] Open
Abstract
In eukaryotes, the 90-kDa heat shock proteins (Hsp90s) are profusely studied chaperones that, together with 70-kDa heat shock proteins (Hsp70s), control protein homeostasis. In bacteria, however, the function of Hsp90 (HtpG) and its collaboration with Hsp70 (DnaK) remains poorly characterized. To uncover physiological processes that depend on HtpG and DnaK, we performed comparative quantitative proteomic analyses of insoluble and total protein fractions from unstressed wild-type (WT) Escherichia coli and from knockout mutants ΔdnaKdnaJ (ΔKJ), ΔhtpG (ΔG), and ΔdnaKdnaJΔhtpG (ΔKJG). Whereas the ΔG mutant showed no detectable proteomic differences with wild-type, ΔKJ expressed more chaperones, proteases and ribosomes and expressed dramatically less metabolic and respiratory enzymes. Unexpectedly, we found that the triple mutant ΔKJG showed higher levels of metabolic and respiratory enzymes than ΔKJ, suggesting that bacterial Hsp90 mediates the degradation of aggregation-prone Hsp70-Hsp40 substrates. Further in vivo experiments suggest that such Hsp90-mediated degradation possibly occurs through the HslUV protease.
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Affiliation(s)
- Bruno Fauvet
- Department of Plant Molecular Biology (DBMV), University of Lausanne, Lausanne, Switzerland
| | - Andrija Finka
- Department of Ecology, Agronomy and Aquaculture, University of Zadar, Zadar, Croatia
| | - Marie-Pierre Castanié-Cornet
- Laboratoire de Microbiologie et de Génétique Moléculaires, Center de Biologie Intégrative, CNRS, Université de Toulouse, Toulouse, France
| | - Anne-Marie Cirinesi
- Laboratoire de Microbiologie et de Génétique Moléculaires, Center de Biologie Intégrative, CNRS, Université de Toulouse, Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, Center de Biologie Intégrative, CNRS, Université de Toulouse, Toulouse, France
| | - Manfredo Quadroni
- Protein Analysis Facility, University of Lausanne, Lausanne, Switzerland
| | - Pierre Goloubinoff
- Department of Plant Molecular Biology (DBMV), University of Lausanne, Lausanne, Switzerland
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4
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Fauvet B, Finka A, Castanié-Cornet MP, Cirinesi AM, Genevaux P, Quadroni M, Goloubinoff P. Bacterial Hsp90 Facilitates the Degradation of Aggregation-Prone Hsp70-Hsp40 Substrates. Front Mol Biosci 2021. [PMID: 33937334 DOI: 10.1101/451989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
In eukaryotes, the 90-kDa heat shock proteins (Hsp90s) are profusely studied chaperones that, together with 70-kDa heat shock proteins (Hsp70s), control protein homeostasis. In bacteria, however, the function of Hsp90 (HtpG) and its collaboration with Hsp70 (DnaK) remains poorly characterized. To uncover physiological processes that depend on HtpG and DnaK, we performed comparative quantitative proteomic analyses of insoluble and total protein fractions from unstressed wild-type (WT) Escherichia coli and from knockout mutants ΔdnaKdnaJ (ΔKJ), ΔhtpG (ΔG), and ΔdnaKdnaJΔhtpG (ΔKJG). Whereas the ΔG mutant showed no detectable proteomic differences with wild-type, ΔKJ expressed more chaperones, proteases and ribosomes and expressed dramatically less metabolic and respiratory enzymes. Unexpectedly, we found that the triple mutant ΔKJG showed higher levels of metabolic and respiratory enzymes than ΔKJ, suggesting that bacterial Hsp90 mediates the degradation of aggregation-prone Hsp70-Hsp40 substrates. Further in vivo experiments suggest that such Hsp90-mediated degradation possibly occurs through the HslUV protease.
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Affiliation(s)
- Bruno Fauvet
- Department of Plant Molecular Biology (DBMV), University of Lausanne, Lausanne, Switzerland
| | - Andrija Finka
- Department of Ecology, Agronomy and Aquaculture, University of Zadar, Zadar, Croatia
| | - Marie-Pierre Castanié-Cornet
- Laboratoire de Microbiologie et de Génétique Moléculaires, Center de Biologie Intégrative, CNRS, Université de Toulouse, Toulouse, France
| | - Anne-Marie Cirinesi
- Laboratoire de Microbiologie et de Génétique Moléculaires, Center de Biologie Intégrative, CNRS, Université de Toulouse, Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, Center de Biologie Intégrative, CNRS, Université de Toulouse, Toulouse, France
| | - Manfredo Quadroni
- Protein Analysis Facility, University of Lausanne, Lausanne, Switzerland
| | - Pierre Goloubinoff
- Department of Plant Molecular Biology (DBMV), University of Lausanne, Lausanne, Switzerland
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5
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Scardaci R, Varese F, Manfredi M, Marengo E, Mazzoli R, Pessione E. Enterococcus faecium NCIMB10415 responds to norepinephrine by altering protein profiles and phenotypic characters. J Proteomics 2020; 231:104003. [PMID: 33038511 DOI: 10.1016/j.jprot.2020.104003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/29/2020] [Accepted: 10/04/2020] [Indexed: 12/13/2022]
Abstract
The long-term established symbiosis between gut microbiota and humans is based upon a dynamic equilibrium that, if unbalanced, could lead to the development of diseases. Despite the huge amount of data concerning the microbiota-gut-brain-axis, little information is available on what happens at the molecular level in bacteria, when exposed to human signals. In the present study, the physiological effects exerted by norepinephrine (NE), a human hormone present in significant amounts in the host gut, were analyzed using the commensal/probiotic strain Enterococcus faecium NCIMB10415 as a target. The aim was to compare the protein profiles of treated and untreated bacteria and relating these proteome patterns to some phenotypic modifications important for bacteria-host interaction. Actually, to date, only pathogens have been considered. Combining a gel-free/label-free proteomic analysis with the evaluation of bile salts resistance, biofilm formation and autoaggregation ability (as well as with the bacterial growth kinetics), allowed to detect changes induced by NE treatment on all the tested probiotic properties. Furthermore, exposure to the bioactive molecule increased the abundance of proteins related to stress response and to host-microbe interaction, such as moonlight proteins involved in adhesion and immune stimulation. The results of this investigation demonstrated that, not only pathogens, but also commensal gut bacteria are affected by host-derived hormones, underlining the importance of a correct cross-signalling in the maintenance of gut homeostasis. SIGNIFICANCE: The crucial role played by the human gut microbiota in ensuring host homeostasis and health is definitively ascertained as suggested by the holobiome concept. The present research was intended to shed light on the endocrinological perturbations possibly affecting microbiota. The microbial model used in this study belongs to Enterococcus faecium species, whose controversial role as gut commensal and opportunistic pathogen in the gut ecosystem is well recognized. The results obtained in the present investigation clearly demonstrate that E. faecium NCIMB10415 can sense and respond to norepinephrine, a human hormone abundant at the gut level, by changing protein profiles and physiology, inducing changes that could favor survival and colonization of the host tissues. To our knowledge, this is the first proteomic report concerning the impact of a human hormone on a commensal/probiotic bacterium, since previous research has focused on exploring the effects of neuroendocrine molecules on growth and virulence of pathogenic species.
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Affiliation(s)
- R Scardaci
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy.
| | - F Varese
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy
| | - M Manfredi
- Center for Translational Research on Autoimmune and Allergic Diseases, Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - E Marengo
- Center for Translational Research on Autoimmune and Allergic Diseases, Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - R Mazzoli
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy
| | - E Pessione
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy.
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6
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Ulrich K, Schwappach B, Jakob U. Thiol-based switching mechanisms of stress-sensing chaperones. Biol Chem 2020; 402:239-252. [PMID: 32990643 DOI: 10.1515/hsz-2020-0262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 09/11/2020] [Indexed: 12/13/2022]
Abstract
Thiol-based redox switches evolved as efficient post-translational regulatory mechanisms that enable individual proteins to rapidly respond to sudden environmental changes. While some protein functions need to be switched off to save resources and avoid potentially error-prone processes, protective functions become essential and need to be switched on. In this review, we focus on thiol-based activation mechanisms of stress-sensing chaperones. Upon stress exposure, these chaperones convert into high affinity binding platforms for unfolding proteins and protect cells against the accumulation of potentially toxic protein aggregates. Their chaperone activity is independent of ATP, a feature that becomes especially important under oxidative stress conditions, where cellular ATP levels drop and canonical ATP-dependent chaperones no longer operate. Vice versa, reductive inactivation and substrate release require the restoration of ATP levels, which ensures refolding of client proteins by ATP-dependent foldases. We will give an overview over the different strategies that cells evolved to rapidly increase the pool of ATP-independent chaperones upon oxidative stress and provide mechanistic insights into how stress conditions are used to convert abundant cellular proteins into ATP-independent holding chaperones.
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Affiliation(s)
- Kathrin Ulrich
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 1105 N. University Ave., Ann Arbor, MI48109, USA
| | - Blanche Schwappach
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 1105 N. University Ave., Ann Arbor, MI48109, USA.,Department of Biological Chemistry, University of Michigan, Ann Arbor, MI48109, USA
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7
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da Cruz Nizer WS, Inkovskiy V, Overhage J. Surviving Reactive Chlorine Stress: Responses of Gram-Negative Bacteria to Hypochlorous Acid. Microorganisms 2020; 8:E1220. [PMID: 32796669 PMCID: PMC7464077 DOI: 10.3390/microorganisms8081220] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 07/30/2020] [Accepted: 08/09/2020] [Indexed: 01/29/2023] Open
Abstract
Sodium hypochlorite (NaOCl) and its active ingredient, hypochlorous acid (HOCl), are the most commonly used chlorine-based disinfectants. HOCl is a fast-acting and potent antimicrobial agent that interacts with several biomolecules, such as sulfur-containing amino acids, lipids, nucleic acids, and membrane components, causing severe cellular damage. It is also produced by the immune system as a first-line of defense against invading pathogens. In this review, we summarize the adaptive responses of Gram-negative bacteria to HOCl-induced stress and highlight the role of chaperone holdases (Hsp33, RidA, Cnox, and polyP) as an immediate response to HOCl stress. We also describe the three identified transcriptional regulators (HypT, RclR, and NemR) that specifically respond to HOCl. Besides the activation of chaperones and transcriptional regulators, the formation of biofilms has been described as an important adaptive response to several stressors, including HOCl. Although the knowledge on the molecular mechanisms involved in HOCl biofilm stimulation is limited, studies have shown that HOCl induces the formation of biofilms by causing conformational changes in membrane properties, overproducing the extracellular polymeric substance (EPS) matrix, and increasing the intracellular concentration of cyclic-di-GMP. In addition, acquisition and expression of antibiotic resistance genes, secretion of virulence factors and induction of the viable but nonculturable (VBNC) state has also been described as an adaptive response to HOCl. In general, the knowledge of how bacteria respond to HOCl stress has increased over time; however, the molecular mechanisms involved in this stress response is still in its infancy. A better understanding of these mechanisms could help understand host-pathogen interactions and target specific genes and molecules to control bacterial spread and colonization.
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Affiliation(s)
| | | | - Joerg Overhage
- Department of Health Sciences, Carleton University, Ottawa, ON K1S 5B6, Canada; (W.S.d.C.N.); (V.I.)
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8
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Barriot R, Latour J, Castanié-Cornet MP, Fichant G, Genevaux P. J-Domain Proteins in Bacteria and Their Viruses. J Mol Biol 2020; 432:3771-3789. [DOI: 10.1016/j.jmb.2020.04.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 02/06/2023]
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9
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Schäfer H, Beckert B, Frese CK, Steinchen W, Nuss AM, Beckstette M, Hantke I, Driller K, Sudzinová P, Krásný L, Kaever V, Dersch P, Bange G, Wilson DN, Turgay K. The alarmones (p)ppGpp are part of the heat shock response of Bacillus subtilis. PLoS Genet 2020; 16:e1008275. [PMID: 32176689 PMCID: PMC7098656 DOI: 10.1371/journal.pgen.1008275] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 03/26/2020] [Accepted: 02/26/2020] [Indexed: 11/24/2022] Open
Abstract
Bacillus subtilis cells are well suited to study how bacteria sense and adapt to proteotoxic stress such as heat, since temperature fluctuations are a major challenge to soil-dwelling bacteria. Here, we show that the alarmones (p)ppGpp, well known second messengers of nutrient starvation, are also involved in the heat stress response as well as the development of thermo-resistance. Upon heat-shock, intracellular levels of (p)ppGpp rise in a rapid but transient manner. The heat-induced (p)ppGpp is primarily produced by the ribosome-associated alarmone synthetase Rel, while the small alarmone synthetases RelP and RelQ seem not to be involved. Furthermore, our study shows that the generated (p)ppGpp pulse primarily acts at the level of translation, and only specific genes are regulated at the transcriptional level. These include the down-regulation of some translation-related genes and the up-regulation of hpf, encoding the ribosome-protecting hibernation-promoting factor. In addition, the alarmones appear to interact with the activity of the stress transcription factor Spx during heat stress. Taken together, our study suggests that (p)ppGpp modulates the translational capacity at elevated temperatures and thereby allows B. subtilis cells to respond to proteotoxic stress, not only by raising the cellular repair capacity, but also by decreasing translation to concurrently reduce the protein load on the cellular protein quality control system.
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Affiliation(s)
- Heinrich Schäfer
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| | - Bertrand Beckert
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | | | - Wieland Steinchen
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Marburg, Germany
| | - Aaron M. Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Michael Beckstette
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ingo Hantke
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | | | - Petra Sudzinová
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Libor Krásný
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Volkhard Kaever
- Hannover Medical School, Research Core Unit Metabolomics, Hannover, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute of Infectiology, University of Münster, Münster, Germany
| | - Gert Bange
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Marburg, Germany
| | - Daniel N. Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Kürşad Turgay
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
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10
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Schramm FD, Schroeder K, Jonas K. Protein aggregation in bacteria. FEMS Microbiol Rev 2020; 44:54-72. [PMID: 31633151 PMCID: PMC7053576 DOI: 10.1093/femsre/fuz026] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 10/17/2019] [Indexed: 02/07/2023] Open
Abstract
Protein aggregation occurs as a consequence of perturbations in protein homeostasis that can be triggered by environmental and cellular stresses. The accumulation of protein aggregates has been associated with aging and other pathologies in eukaryotes, and in bacteria with changes in growth rate, stress resistance and virulence. Numerous past studies, mostly performed in Escherichia coli, have led to a detailed understanding of the functions of the bacterial protein quality control machinery in preventing and reversing protein aggregation. However, more recent research points toward unexpected diversity in how phylogenetically different bacteria utilize components of this machinery to cope with protein aggregation. Furthermore, how persistent protein aggregates localize and are passed on to progeny during cell division and how their presence impacts reproduction and the fitness of bacterial populations remains a controversial field of research. Finally, although protein aggregation is generally seen as a symptom of stress, recent work suggests that aggregation of specific proteins under certain conditions can regulate gene expression and cellular resource allocation. This review discusses recent advances in understanding the consequences of protein aggregation and how this process is dealt with in bacteria, with focus on highlighting the differences and similarities observed between phylogenetically different groups of bacteria.
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Affiliation(s)
- Frederic D Schramm
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm 10691, Sweden
| | - Kristen Schroeder
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm 10691, Sweden
| | - Kristina Jonas
- Science for Life Laboratory and Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, Stockholm 10691, Sweden
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11
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Garofalo R, Wohlgemuth I, Pearson M, Lenz C, Urlaub H, Rodnina MV. Broad range of missense error frequencies in cellular proteins. Nucleic Acids Res 2019; 47:2932-2945. [PMID: 30649420 PMCID: PMC6451103 DOI: 10.1093/nar/gky1319] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/21/2018] [Accepted: 12/30/2018] [Indexed: 12/25/2022] Open
Abstract
Assessment of the fidelity of gene expression is crucial to understand cell homeostasis. Here we present a highly sensitive method for the systematic Quantification of Rare Amino acid Substitutions (QRAS) using absolute quantification by targeted mass spectrometry after chromatographic enrichment of peptides with missense amino acid substitutions. By analyzing incorporation of near- and non-cognate amino acids in a model protein EF-Tu, we show that most of missense errors are too rare to detect by conventional methods, such as DDA, and are estimated to be between <10−7–10-5 by QRAS. We also observe error hotspots of up to 10−3 for some types of mismatches, including the G-U mismatch. The error frequency depends on the expression level of EF-Tu and, surprisingly, the amino acid position in the protein. QRAS is not restricted to any particular miscoding event, organism, strain or model protein and is a reliable tool to analyze very rare proteogenomic events.
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Affiliation(s)
- Raffaella Garofalo
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen, Germany
| | - Ingo Wohlgemuth
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen, Germany
| | - Michael Pearson
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen, Germany
| | - Christof Lenz
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen, Germany.,Department of Clinical Chemistry, Bioanalytics, University Medical Center Goettingen, Robert-Koch-Straße 40, 37075 Goettingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen, Germany.,Department of Clinical Chemistry, Bioanalytics, University Medical Center Goettingen, Robert-Koch-Straße 40, 37075 Goettingen, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen, Germany
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12
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Unique Unfoldase/Aggregase Activity of a Molecular Chaperone Hsp33 in its Holding-Inactive State. J Mol Biol 2019; 431:1468-1480. [DOI: 10.1016/j.jmb.2019.02.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/12/2019] [Accepted: 02/18/2019] [Indexed: 11/21/2022]
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13
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Schramm FD, Heinrich K, Thüring M, Bernhardt J, Jonas K. An essential regulatory function of the DnaK chaperone dictates the decision between proliferation and maintenance in Caulobacter crescentus. PLoS Genet 2017; 13:e1007148. [PMID: 29281627 PMCID: PMC5760092 DOI: 10.1371/journal.pgen.1007148] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 01/09/2018] [Accepted: 12/11/2017] [Indexed: 11/19/2022] Open
Abstract
Hsp70 chaperones are well known for their important functions in maintaining protein homeostasis during thermal stress conditions. In many bacteria the Hsp70 homolog DnaK is also required for growth in the absence of stress. The molecular reasons underlying Hsp70 essentiality remain in most cases unclear. Here, we demonstrate that DnaK is essential in the α-proteobacterium Caulobacter crescentus due to its regulatory function in gene expression. Using a suppressor screen we identified mutations that allow growth in the absence of DnaK. All mutations reduced the activity of the heat shock sigma factor σ32, demonstrating that the DnaK-dependent inactivation of σ32 is a growth requirement. While most mutations occurred in the rpoH gene encoding σ32, we also identified mutations affecting σ32 activity or stability in trans, providing important new insight into the regulatory mechanisms controlling σ32 activity. Most notably, we describe a mutation in the ATP dependent protease HslUV that induces rapid degradation of σ32, and a mutation leading to increased levels of the house keeping σ70 that outcompete σ32 for binding to the RNA polymerase. We demonstrate that σ32 inhibits growth and that its unrestrained activity leads to an extensive reprogramming of global gene expression, resulting in upregulation of repair and maintenance functions and downregulation of the growth-promoting functions of protein translation, DNA replication and certain metabolic processes. While this re-allocation from proliferative to maintenance functions could provide an advantage during heat stress, it leads to growth defects under favorable conditions. We conclude that Caulobacter has co-opted the DnaK chaperone system as an essential regulator of gene expression under conditions when its folding activity is dispensable. Molecular chaperones of the Hsp70 family belong to the most conserved cellular machineries throughout the tree of life. These proteins play key roles in maintaining protein homeostasis, especially under heat stress conditions. In diverse bacteria the Hsp70 homolog DnaK is essential for growth even in the absence of stress. However, the molecular mechanisms underlying the essential nature of DnaK have in most cases not been studied. We found in the α-proteobacterium Caulobacter crescentus that the function of DnaK as a folding catalyst is dispensable in the absence of stress. Instead, its sole essential function under such conditions is to inhibit the activity of the heat shock sigma factor σ32. Our findings highlight that some bacteria have co-opted chaperones as essential regulators of gene expression under conditions when their folding activity is not required. Furthermore, our work illustrates that essential genes can perform different essential functions in discrete growth conditions.
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Affiliation(s)
- Frederic D. Schramm
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, Marburg, Germany
| | - Kristina Heinrich
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, Marburg, Germany
| | - Marietta Thüring
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, Marburg, Germany
| | - Jörg Bernhardt
- Institute of Microbiology, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany
| | - Kristina Jonas
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, Marburg, Germany
- * E-mail:
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14
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Rimon O, Suss O, Goldenberg M, Fassler R, Yogev O, Amartely H, Propper G, Friedler A, Reichmann D. A Role of Metastable Regions and Their Connectivity in the Inactivation of a Redox-Regulated Chaperone and Its Inter-Chaperone Crosstalk. Antioxid Redox Signal 2017; 27:1252-1267. [PMID: 28394178 DOI: 10.1089/ars.2016.6900] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS A recently discovered group of conditionally disordered chaperones share a very unique feature; they need to lose structure to become active as chaperones. This activation mechanism makes these chaperones particularly suited to respond to protein-unfolding stress conditions, such as oxidative unfolding. However, the role of this disorder in stress-related activation, chaperone function, and the crosstalk with other chaperone systems is not yet clear. Here, we focus on one of the members of the conditionally disordered chaperones, a thiol-redox switch of the bacterial proteostasis system, Hsp33. RESULTS By modifying the Hsp33's sequence, we reveal that the metastable region has evolved to abolish redox-dependent chaperone activity, rather than enhance binding affinity for client proteins. The intrinsically disordered region of Hsp33 serves as an anchor for the reduced, inactive state of Hsp33, and it dramatically affects the crosstalk with the synergetic chaperone system, DnaK/J. Using mass spectrometry, we describe the role that the metastable region plays in determining client specificity during normal and oxidative stress conditions in the cell. Innovation and Conclusion: We uncover a new role of protein plasticity in Hsp33's inactivation, client specificity, crosstalk with the synergistic chaperone system DnaK/J, and oxidative stress-specific interactions in bacteria. Our results also suggest that Hsp33 might serve as a member of the house-keeping proteostasis machinery, tasked with maintaining a "healthy" proteome during normal conditions, and that this function does not depend on the metastable linker region. Antioxid. Redox Signal. 27, 1252-1267.
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Affiliation(s)
- Oded Rimon
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Ohad Suss
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Mor Goldenberg
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Rosi Fassler
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Ohad Yogev
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Hadar Amartely
- 2 Institute of Chemistry, The Hebrew University of Jerusalem , Safra Campus Givat Ram, Jerusalem, Israel
| | - Guy Propper
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Assaf Friedler
- 2 Institute of Chemistry, The Hebrew University of Jerusalem , Safra Campus Givat Ram, Jerusalem, Israel
| | - Dana Reichmann
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
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15
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Directed evolution of SecB chaperones toward toxin-antitoxin systems. Proc Natl Acad Sci U S A 2017; 114:12584-12589. [PMID: 29114057 DOI: 10.1073/pnas.1710456114] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
SecB chaperones assist protein export in bacteria. However, certain SecB family members have diverged to become specialized toward the control of toxin-antitoxin (TA) systems known to promote bacterial adaptation to stress and persistence. In such tripartite TA-chaperone (TAC) systems, the chaperone was shown to assist folding and to prevent degradation of its cognate antitoxin, thus facilitating inhibition of the toxin. Here, we used both the export chaperone SecB of Escherichia coli and the tripartite TAC system of Mycobacterium tuberculosis as a model to investigate how generic chaperones can specialize toward the control of TA systems. Through directed evolution of SecB, we have identified and characterized mutations that specifically improve the ability of SecB to control our model TA system without affecting its function in protein export. Such a remarkable plasticity of SecB chaperone function suggests that its substrate binding surface can be readily remodeled to accommodate specific clients.
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16
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Voth W, Jakob U. Stress-Activated Chaperones: A First Line of Defense. Trends Biochem Sci 2017; 42:899-913. [PMID: 28893460 DOI: 10.1016/j.tibs.2017.08.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/18/2017] [Accepted: 08/21/2017] [Indexed: 10/18/2022]
Abstract
Proteins are constantly challenged by environmental stress conditions that threaten their structure and function. Especially problematic are oxidative, acid, and severe heat stress which induce very rapid and widespread protein unfolding and generate conditions that make canonical chaperones and/or transcriptional responses inadequate to protect the proteome. We review here recent advances in identifying and characterizing stress-activated chaperones which are inactive under non-stress conditions but become potent chaperones under specific protein-unfolding stress conditions. We discuss the post-translational mechanisms by which these chaperones sense stress, and consider the role that intrinsic disorder plays in their regulation and function. We examine their physiological roles under both non-stress and stress conditions, their integration into the cellular proteostasis network, and their potential as novel therapeutic targets.
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Affiliation(s)
- Wilhelm Voth
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular Biology, Universitätsmedizin Göttingen, 37073 Göttingen, Germany
| | - Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
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17
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Anglès F, Castanié-Cornet MP, Slama N, Dinclaux M, Cirinesi AM, Portais JC, Létisse F, Genevaux P. Multilevel interaction of the DnaK/DnaJ(HSP70/HSP40) stress-responsive chaperone machine with the central metabolism. Sci Rep 2017; 7:41341. [PMID: 28128357 PMCID: PMC5269706 DOI: 10.1038/srep41341] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 12/16/2016] [Indexed: 12/23/2022] Open
Abstract
Networks of molecular chaperones maintain cellular protein homeostasis by acting at nearly every step in the biogenesis of proteins and protein complexes. Herein, we demonstrate that the major chaperone DnaK/HSP70 of the model bacterium Escherichia coli is critical for the proper functioning of the central metabolism and for the cellular response to carbon nutrition changes, either directly or indirectly via the control of the heat-shock response. We identified carbon sources whose utilization was positively or negatively affected by DnaK and isolated several central metabolism genes (among other genes identified in this work) that compensate for the lack of DnaK and/or DnaK/Trigger Factor chaperone functions in vivo. Using carbon sources with specific entry points coupled to NMR analyses of real-time carbon assimilation, metabolic coproducts production and flux rearrangements, we demonstrate that DnaK significantly impacts the hierarchical order of carbon sources utilization, the excretion of main coproducts and the distribution of metabolic fluxes, thus revealing a multilevel interaction of DnaK with the central metabolism.
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Affiliation(s)
- Fréderic Anglès
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse Cedex 9, France.,LISBP, Université de Toulouse, CNRS, INRA, INSA F-31400 Toulouse, France
| | - Marie-Pierre Castanié-Cornet
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
| | - Nawel Slama
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
| | - Mickael Dinclaux
- LISBP, Université de Toulouse, CNRS, INRA, INSA F-31400 Toulouse, France
| | - Anne-Marie Cirinesi
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
| | | | - Fabien Létisse
- LISBP, Université de Toulouse, CNRS, INRA, INSA F-31400 Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
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18
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Groitl B, Horowitz S, Makepeace KAT, Petrotchenko EV, Borchers CH, Reichmann D, Bardwell JCA, Jakob U. Protein unfolding as a switch from self-recognition to high-affinity client binding. Nat Commun 2016; 7:10357. [PMID: 26787517 PMCID: PMC4735815 DOI: 10.1038/ncomms10357] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/02/2015] [Indexed: 01/20/2023] Open
Abstract
Stress-specific activation of the chaperone Hsp33 requires the unfolding of a central linker region. This activation mechanism suggests an intriguing functional relationship between the chaperone's own partial unfolding and its ability to bind other partially folded client proteins. However, identifying where Hsp33 binds its clients has remained a major gap in our understanding of Hsp33's working mechanism. By using site-specific Fluorine-19 nuclear magnetic resonance experiments guided by in vivo crosslinking studies, we now reveal that the partial unfolding of Hsp33's linker region facilitates client binding to an amphipathic docking surface on Hsp33. Furthermore, our results provide experimental evidence for the direct involvement of conditionally disordered regions in unfolded protein binding. The observed structural similarities between Hsp33's own metastable linker region and client proteins present a possible model for how Hsp33 uses protein unfolding as a switch from self-recognition to high-affinity client binding. Under stress conditions the molecular chaperone Hsp33 is activated to process unfolded proteins. Here, the authors use in vivo and in vitro crosslinking and 19F-NMR to elucidate the binding site for misfolded proteins and are able to propose a model for its mechanism of action.
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Affiliation(s)
- Bastian Groitl
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N-University Avenue, Ann Arbor, Michigan 48109-1048, USA
| | - Scott Horowitz
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N-University Avenue, Ann Arbor, Michigan 48109-1048, USA.,Howard Hughes Medical Institute, University of Michigan, 830 N-University Avenue, Ann Arbor, Michigan 48109-1048, USA
| | - Karl A T Makepeace
- Department of Biochemistry and Microbiology, Genome BC Proteomics Centre, University of Victoria, 4464 Markham Street #3101, Victoria, British Columbia, Canada V8Z5N3
| | - Evgeniy V Petrotchenko
- Department of Biochemistry and Microbiology, Genome BC Proteomics Centre, University of Victoria, 4464 Markham Street #3101, Victoria, British Columbia, Canada V8Z5N3
| | - Christoph H Borchers
- Department of Biochemistry and Microbiology, Genome BC Proteomics Centre, University of Victoria, 4464 Markham Street #3101, Victoria, British Columbia, Canada V8Z5N3
| | - Dana Reichmann
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N-University Avenue, Ann Arbor, Michigan 48109-1048, USA
| | - James C A Bardwell
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N-University Avenue, Ann Arbor, Michigan 48109-1048, USA.,Howard Hughes Medical Institute, University of Michigan, 830 N-University Avenue, Ann Arbor, Michigan 48109-1048, USA
| | - Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N-University Avenue, Ann Arbor, Michigan 48109-1048, USA
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19
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Lee YS, Lee J, Ryu KS, Lee Y, Jung TG, Jang JH, Sim DW, Kim EH, Seo MD, Lee KW, Won HS. Semi-Empirical Structure Determination of Escherichia coli Hsp33 and Identification of Dynamic Regulatory Elements for the Activation Process. J Mol Biol 2015; 427:3850-61. [DOI: 10.1016/j.jmb.2015.09.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 09/21/2015] [Accepted: 09/30/2015] [Indexed: 11/27/2022]
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20
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Abstract
Microorganisms live in fluctuating environments, requiring stress response pathways to resist environmental insults and stress. These pathways dynamically monitor cellular status, and mediate adaptive changes by remodeling the proteome, largely accomplished by remodeling transcriptional networks and protein degradation. The complementarity of fast, specific proteolytic degradation and slower, broad transcriptomic changes gives cells the mechanistic repertoire to dynamically adjust cellular processes and optimize response behavior. Together, this enables cells to minimize the 'cost' of the response while maximizing the ability to survive environmental stress. Here we highlight recent progress in our understanding of transcriptional networks and proteolysis that illustrates the design principles used by bacteria to generate the complex behaviors required to resist stress.
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21
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An essential nonredundant role for mycobacterial DnaK in native protein folding. PLoS Genet 2014; 10:e1004516. [PMID: 25058675 PMCID: PMC4109909 DOI: 10.1371/journal.pgen.1004516] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 06/02/2014] [Indexed: 12/13/2022] Open
Abstract
Protein chaperones are essential in all domains of life to prevent and resolve protein misfolding during translation and proteotoxic stress. HSP70 family chaperones, including E. coli DnaK, function in stress induced protein refolding and degradation, but are dispensable for cellular viability due to redundant chaperone systems that prevent global nascent peptide insolubility. However, the function of HSP70 chaperones in mycobacteria, a genus that includes multiple human pathogens, has not been examined. We find that mycobacterial DnaK is essential for cell growth and required for native protein folding in Mycobacterium smegmatis. Loss of DnaK is accompanied by proteotoxic collapse characterized by the accumulation of insoluble newly synthesized proteins. DnaK is required for solubility of large multimodular lipid synthases, including the essential lipid synthase FASI, and DnaK loss is accompanied by disruption of membrane structure and increased cell permeability. Trigger Factor is nonessential and has a minor role in native protein folding that is only evident in the absence of DnaK. In unstressed cells, DnaK localizes to multiple, dynamic foci, but relocalizes to focal protein aggregates during stationary phase or upon expression of aggregating peptides. Mycobacterial cells restart cell growth after proteotoxic stress by isolating persistent DnaK containing protein aggregates away from daughter cells. These results reveal unanticipated essential nonredunant roles for mycobacterial DnaK in mycobacteria and indicate that DnaK defines a unique susceptibility point in the mycobacterial proteostasis network. All living organisms use protein chaperones to prevent proteins from becoming insoluble either spontaneously or during cellular stress that can damage proteins. The HSP70 chaperone DnaK has been well characterized in E. coli and is important for that bacterium to resist protein denaturation from heat, but is dispensable for cell growth in the absence of stress due to redundancy with other chaperone systems. However, the function of chaperones in bacterial pathogens, which are exposed to protein stress within the host, has received less attention. Here we examine the function of DnaK in mycobacteria, a genus that includes multiple human pathogens, and find that DnaK is required for cell growth. This essential function is due to a lack of redundancy with other chaperone systems for the folding of proteins, even in the absence of stress. These findings expand the paradigm of DnaK function and identify DnaK as a promising target for antibiotic development for mycobacteria.
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22
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Multiple toxin-antitoxin systems in Mycobacterium tuberculosis. Toxins (Basel) 2014; 6:1002-20. [PMID: 24662523 PMCID: PMC3968373 DOI: 10.3390/toxins6031002] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/20/2014] [Accepted: 02/24/2014] [Indexed: 12/26/2022] Open
Abstract
The hallmark of Mycobacterium tuberculosis is its ability to persist for a long-term in host granulomas, in a non-replicating and drug-tolerant state, and later awaken to cause disease. To date, the cellular factors and the molecular mechanisms that mediate entry into the persistence phase are poorly understood. Remarkably, M. tuberculosis possesses a very high number of toxin-antitoxin (TA) systems in its chromosome, 79 in total, regrouping both well-known (68) and novel (11) families, with some of them being strongly induced in drug-tolerant persisters. In agreement with the capacity of stress-responsive TA systems to generate persisters in other bacteria, it has been proposed that activation of TA systems in M. tuberculosis could contribute to its pathogenesis. Herein, we review the current knowledge on the multiple TA families present in this bacterium, their mechanism, and their potential role in physiology and virulence.
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23
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Verhagen LM, de Jonge MI, Burghout P, Schraa K, Spagnuolo L, Mennens S, Eleveld MJ, van der Gaast-de Jongh CE, Zomer A, Hermans PWM, Bootsma HJ. Genome-wide identification of genes essential for the survival of Streptococcus pneumoniae in human saliva. PLoS One 2014; 9:e89541. [PMID: 24586856 PMCID: PMC3934895 DOI: 10.1371/journal.pone.0089541] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 01/22/2014] [Indexed: 11/19/2022] Open
Abstract
Since Streptococcus pneumoniae transmits through droplet spread, this respiratory tract pathogen may be able to survive in saliva. Here, we show that saliva supports survival of clinically relevant S. pneumoniae strains for more than 24 h in a capsule-independent manner. Moreover, saliva induced growth of S. pneumoniae in growth-permissive conditions, suggesting that S. pneumoniae is well adapted for uptake of nutrients from this bodily fluid. By using Tn-seq, a method for genome-wide negative selection screening, we identified 147 genes potentially required for growth and survival of S. pneumoniae in saliva, among which genes predicted to be involved in cell envelope biosynthesis, cell transport, amino acid metabolism, and stress response predominated. The Tn-seq findings were validated by testing a panel of directed gene deletion mutants for their ability to survive in saliva under two testing conditions: at room temperature without CO2, representing transmission, and at 37°C with CO2, representing in-host carriage. These validation experiments confirmed that the plsX gene and the amiACDEF and aroDEBC operons, involved in respectively fatty acid metabolism, oligopeptide transport, and biosynthesis of aromatic amino acids play an important role in the growth and survival of S. pneumoniae in saliva at 37°C. In conclusion, this study shows that S. pneumoniae is well-adapted for growth and survival in human saliva and provides a genome-wide list of genes potentially involved in adaptation. This notion supports earlier evidence that S. pneumoniae can use human saliva as a vector for transmission.
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Affiliation(s)
- Lilly M. Verhagen
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Marien I. de Jonge
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Peter Burghout
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Kiki Schraa
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Lorenza Spagnuolo
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Svenja Mennens
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Marc J. Eleveld
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | | | - Aldert Zomer
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Peter W. M. Hermans
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Hester J. Bootsma
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
- * E-mail:
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24
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Castanié-Cornet MP, Bruel N, Genevaux P. Chaperone networking facilitates protein targeting to the bacterial cytoplasmic membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:1442-56. [PMID: 24269840 DOI: 10.1016/j.bbamcr.2013.11.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/10/2013] [Accepted: 11/13/2013] [Indexed: 12/22/2022]
Abstract
Nascent polypeptides emerging from the ribosome are assisted by a pool of molecular chaperones and targeting factors, which enable them to efficiently partition as cytosolic, integral membrane or exported proteins. Extensive genetic and biochemical analyses have significantly expanded our knowledge of chaperone tasking throughout this process. In bacteria, it is known that the folding of newly-synthesized cytosolic proteins is mainly orchestrated by three highly conserved molecular chaperones, namely Trigger Factor (TF), DnaK (HSP70) and GroEL (HSP60). Yet, it has been reported that these major chaperones are strongly involved in protein translocation pathways as well. This review describes such essential molecular chaperone functions, with emphasis on both the biogenesis of inner membrane proteins and the post-translational targeting of presecretory proteins to the Sec and the twin-arginine translocation (Tat) pathways. Critical interplay between TF, DnaK, GroEL and other molecular chaperones and targeting factors, including SecB, SecA, the signal recognition particle (SRP) and the redox enzyme maturation proteins (REMPs) is also discussed. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Affiliation(s)
- Marie-Pierre Castanié-Cornet
- Laboratoire de Microbiologie et Génétique Moléculaire (LMGM), Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, Toulouse, France
| | - Nicolas Bruel
- Laboratoire de Microbiologie et Génétique Moléculaire (LMGM), Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaire (LMGM), Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, Toulouse, France.
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25
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Jonas K, Liu J, Chien P, Laub MT. Proteotoxic stress induces a cell-cycle arrest by stimulating Lon to degrade the replication initiator DnaA. Cell 2013; 154:623-36. [PMID: 23911325 DOI: 10.1016/j.cell.2013.06.034] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/15/2013] [Accepted: 06/20/2013] [Indexed: 10/26/2022]
Abstract
The decision to initiate DNA replication is a critical step in the cell cycle of all organisms. Cells often delay replication in the face of stressful conditions, but the underlying mechanisms remain incompletely defined. Here, we demonstrate in Caulobacter crescentus that proteotoxic stress induces a cell-cycle arrest by triggering the degradation of DnaA, the conserved replication initiator. A depletion of available Hsp70 chaperone, DnaK, either through genetic manipulation or heat shock, induces synthesis of the Lon protease, which can directly degrade DnaA. Unexpectedly, we find that unfolded proteins, which accumulate following a loss of DnaK, also allosterically activate Lon to degrade DnaA, thereby ensuring a cell-cycle arrest. Our work reveals a mechanism for regulating DNA replication under adverse growth conditions. Additionally, our data indicate that unfolded proteins can actively and directly alter substrate recognition by cellular proteases.
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Affiliation(s)
- Kristina Jonas
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Sala A, Calderon V, Bordes P, Genevaux P. TAC from Mycobacterium tuberculosis: a paradigm for stress-responsive toxin-antitoxin systems controlled by SecB-like chaperones. Cell Stress Chaperones 2013; 18:129-35. [PMID: 23264229 PMCID: PMC3581621 DOI: 10.1007/s12192-012-0396-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/05/2012] [Accepted: 12/06/2012] [Indexed: 01/27/2023] Open
Abstract
Bacterial type II toxin-antitoxins (TAs) are two-component systems that modulate growth in response to specific stress conditions, thus promoting adaptation and persistence. The major human pathogen Mycobacterium tuberculosis potentially encodes 75 TAs and it has been proposed that persistence induced by active toxins might be relevant for its pathogenesis. In this work, we focus on the newly discovered toxin-antitoxin-chaperone (TAC) system of M. tuberculosis, an atypical stress-responsive TA system tightly controlled by a molecular chaperone that shows similarity to the canonical SecB chaperone involved in Sec-dependent protein export in Gram-negative bacteria. We performed a large-scale genome screening to reconstruct the evolutionary history of TAC systems and found that TAC is not restricted to mycobacteria and seems to have disseminated in diverse taxonomic groups by horizontal gene transfer. Our results suggest that TAC chaperones are evolutionary related to the solitary chaperone SecB and have diverged to become specialized toward their cognate antitoxins.
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Affiliation(s)
- Ambre Sala
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre National de la Recherche Scientifique and Université Paul Sabatier, 31000 Toulouse, France
| | - Virginie Calderon
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre National de la Recherche Scientifique and Université Paul Sabatier, 31000 Toulouse, France
| | - Patricia Bordes
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre National de la Recherche Scientifique and Université Paul Sabatier, 31000 Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre National de la Recherche Scientifique and Université Paul Sabatier, 31000 Toulouse, France
- Laboratoire de Microbiologie et Génétique Moléculaires, IBCG, CNRS, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse cedex 09, France
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